In air traffic the security of vehicles is of crucial importance. Each vehicle is monitored for malfunctions and irregularities between flights and great effort is made to keep and improve the security during maintenance.
For the detection of cracks on surfaces or in junction points of components of an aircraft different sensors may be employed. For example, electric probes may be used which change their electric properties due to the formation of a crack. However, such sensors need a power supply and are to be connected to an analyzing unit for crack detection. It may be necessary to traverse large distances to the analyzing unit. Thus, the cabling can be time, space, weight and cost consuming. Furthermore, the maintenance of the power supply may be time consuming.